Is it possible to swap just the cats of the stock exhaust? Cut it by the welds and then weld a 100cpsi cats? By the pics, it seems a straight swap for any good exhaust welder.







This FVD cats have 105mm(diameter)x100mm(lenght). Does anyone know the size of the stocks?

 

Outside of the added labor costs for cutting, welding etc. there is a good chance you will have rattling issues swapping out cores like that. I would just go full exhaust and take advantage of the higher flow and lighter weight before hacking up a perfectly find oem exhaust - dont forget, you might need to install it again.

 

I have a local exhaust shop that made some custom exhausts in my previous cars and friends cars (cut and weld labour included) and never had/heard any problems of their exhausts. I'm not a weight saving freak, or a trackdays guy, so i doubt that 30lbs will do a thing in straight line performance, and everybody knows that the restritions of the stock exhaust is in the 600cpsi cats. It is also so tempting spending $500 in this mod, than $3k in a box with sport cats for similar power gains.
Another advantage will be that it will keep the stock look for the dealer.

 

If you want cats that flow well and dont throw codes on the TT (i.e. emitec or the German made trimetal type used by most of the good exhausts) your looking at much more than $500 in parts alone however. Im not sure if anyone has a 100 that jives with the TT without throwing a code.

 

These 100 cell cats will be way too small. You'll find all the answers about the stock cats and the sport cats on the Europipe website.
http://www.europipe.be

 

100 cells will also trigger CELs on the 997TT unless you tune for them or use a few tricks...

 

I would pitch the stock exhaust and go with 100-200 cell cats and exhaust bypass straight pipes. It will save mega weight and money. Be advised the sound is very loud at startup and there is a significant drone at highway speeds. The performance is more than worth the annoyance in my opinion. I actually have gotten were I like the sound esp at WOT.

 

That is what i was thinking: random 100cells with extended bungs. I think that my neighbours will be upset with straight pipes, and once again my goal is only a deeper sound, increasing hp and keep the stock look. Keep it like a sleeper, if that is possible with the 997TT

 

Good 100 cell cats won't cause any problems,no check engine lights with Europipe exhaust...

 

Thanks for that info. I spoke with exhaust shop owner and he said that it will be a easy job. He also said that it won't be a problem if i buy it a bit bigger. And that i just have to be careful about the lenght (shorter or the same size only). As i only saw 105mm - 108mm - 118mm - 130mm, i think that i will give a shot at the 130mm diameter sport cats...

 

You would have high flow cats that then pour exhaust flow to a bottleneck restricted muffler. As Sharky said, 100cell will throw a CEL, that is why people will flash the car at the same time too.